CVE-2024-27399

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout There is a race condition between l2cap_chan_timeout() and l2cap_chan_del(). When we use l2cap_chan_del() to delete the channel, the chan->conn will be set to null. But the conn could be dereferenced again in the mutex_lock() of l2cap_chan_timeout(). As a result the null pointer dereference bug will happen. The KASAN report triggered by POC is shown below: [ 472.074580] ================================================================== [ 472.075284] BUG: KASAN: null-ptr-deref in mutex_lock+0x68/0xc0 [ 472.075308] Write of size 8 at addr 0000000000000158 by task kworker/0:0/7 [ 472.075308] [ 472.075308] CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.9.0-rc5-00356-g78c0094a146b #36 [ 472.075308] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4 [ 472.075308] Workqueue: events l2cap_chan_timeout [ 472.075308] Call Trace: [ 472.075308] <TASK> [ 472.075308] dump_stack_lvl+0x137/0x1a0 [ 472.075308] print_report+0x101/0x250 [ 472.075308] ? __virt_addr_valid+0x77/0x160 [ 472.075308] ? mutex_lock+0x68/0xc0 [ 472.075308] kasan_report+0x139/0x170 [ 472.075308] ? mutex_lock+0x68/0xc0 [ 472.075308] kasan_check_range+0x2c3/0x2e0 [ 472.075308] mutex_lock+0x68/0xc0 [ 472.075308] l2cap_chan_timeout+0x181/0x300 [ 472.075308] process_one_work+0x5d2/0xe00 [ 472.075308] worker_thread+0xe1d/0x1660 [ 472.075308] ? pr_cont_work+0x5e0/0x5e0 [ 472.075308] kthread+0x2b7/0x350 [ 472.075308] ? pr_cont_work+0x5e0/0x5e0 [ 472.075308] ? kthread_blkcg+0xd0/0xd0 [ 472.075308] ret_from_fork+0x4d/0x80 [ 472.075308] ? kthread_blkcg+0xd0/0xd0 [ 472.075308] ret_from_fork_asm+0x11/0x20 [ 472.075308] </TASK> [ 472.075308] ================================================================== [ 472.094860] Disabling lock debugging due to kernel taint [ 472.096136] BUG: kernel NULL pointer dereference, address: 0000000000000158 [ 472.096136] #PF: supervisor write access in kernel mode [ 472.096136] #PF: error_code(0x0002) - not-present page [ 472.096136] PGD 0 P4D 0 [ 472.096136] Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI [ 472.096136] CPU: 0 PID: 7 Comm: kworker/0:0 Tainted: G B 6.9.0-rc5-00356-g78c0094a146b #36 [ 472.096136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4 [ 472.096136] Workqueue: events l2cap_chan_timeout [ 472.096136] RIP: 0010:mutex_lock+0x88/0xc0 [ 472.096136] Code: be 08 00 00 00 e8 f8 23 1f fd 4c 89 f7 be 08 00 00 00 e8 eb 23 1f fd 42 80 3c 23 00 74 08 48 88 [ 472.096136] RSP: 0018:ffff88800744fc78 EFLAGS: 00000246 [ 472.096136] RAX: 0000000000000000 RBX: 1ffff11000e89f8f RCX: ffffffff8457c865 [ 472.096136] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88800744fc78 [ 472.096136] RBP: 0000000000000158 R08: ffff88800744fc7f R09: 1ffff11000e89f8f [ 472.096136] R10: dffffc0000000000 R11: ffffed1000e89f90 R12: dffffc0000000000 [ 472.096136] R13: 0000000000000158 R14: ffff88800744fc78 R15: ffff888007405a00 [ 472.096136] FS: 0000000000000000(0000) GS:ffff88806d200000(0000) knlGS:0000000000000000 [ 472.096136] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 472.096136] CR2: 0000000000000158 CR3: 000000000da32000 CR4: 00000000000006f0 [ 472.096136] Call Trace: [ 472.096136] <TASK> [ 472.096136] ? __die_body+0x8d/0xe0 [ 472.096136] ? page_fault_oops+0x6b8/0x9a0 [ 472.096136] ? kernelmode_fixup_or_oops+0x20c/0x2a0 [ 472.096136] ? do_user_addr_fault+0x1027/0x1340 [ 472.096136] ? _printk+0x7a/0xa0 [ 472.096136] ? mutex_lock+0x68/0xc0 [ 472.096136] ? add_taint+0x42/0xd0 [ 472.096136] ? exc_page_fault+0x6a/0x1b0 [ 472.096136] ? asm_exc_page_fault+0x26/0x30 [ 472.096136] ? mutex_lock+0x75/0xc0 [ 472.096136] ? mutex_lock+0x88/0xc0 [ 472.096136] ? mutex_lock+0x75/0xc0 [ 472.096136] l2cap_chan_timeo ---truncated---

CVSS Metrics

• v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.30%• Percentile: 23%

Techniques & Countermeasures

• CWE-476•NULL Pointer Dereference

  The product dereferences a pointer that it expects to be valid but is NULL.

Affected Systems

• debian•linux

  < 5.10.218-1 | < 6.1.94-1 | < 6.8.11-1 | < 6.8.11-1

• ubuntu•linux

  all | < 5.4.0-192.212 | < 5.15.0-118.128 | < 6.8.0-40.40

• ubuntu•linux-allwinner-5.19

  all

• ubuntu•linux-aws

  all | < 5.4.0-1130.140 | < 5.15.0-1067.73 | < 6.8.0-1013.14

• ubuntu•linux-aws-5.0

  all

• ubuntu•linux-aws-5.11

  all

• ubuntu•linux-aws-5.13

  all

• ubuntu•linux-aws-5.15

  < 5.15.0-1067.73~20.04.1

• ubuntu•linux-aws-5.19

  all

• ubuntu•linux-aws-5.3

  all

• ubuntu•linux-aws-5.4

  < 5.4.0-1130.140~18.04.1

• ubuntu•linux-aws-5.8

  all

• ubuntu•linux-aws-6.2

  all

• ubuntu•linux-aws-6.5

  all

• ubuntu•linux-aws-6.8

  < 6.8.0-1013.14~22.04.1

• ubuntu•linux-aws-fips

  all | < 5.4.0-1130.140+fips1 | < 5.15.0-1067.73+fips1

• ubuntu•linux-aws-hwe

  all

• ubuntu•linux-azure

  all | all | < 5.4.0-1135.142 | < 5.15.0-1070.79 | < 6.8.0-1012.14

• ubuntu•linux-azure-4.15

  all

• ubuntu•linux-azure-5.11

  all

• ubuntu•linux-azure-5.13

  all

• ubuntu•linux-azure-5.15

  < 5.15.0-1070.79~20.04.1

• ubuntu•linux-azure-5.19

  all

• ubuntu•linux-azure-5.3

  all

• ubuntu•linux-azure-5.4

  < 5.4.0-1135.142~18.04.1

• ubuntu•linux-azure-5.8

  all

• ubuntu•linux-azure-6.2

  all

• ubuntu•linux-azure-6.5

  all

• ubuntu•linux-azure-6.8

  < 6.8.0-1012.14~22.04.1

• ubuntu•linux-azure-edge

  all

• ubuntu•linux-azure-fde

  all | < 5.15.0-1070.79.1

• ubuntu•linux-azure-fde-5.19

  all

• ubuntu•linux-azure-fde-6.2

  all

• ubuntu•linux-azure-fips

  all | < 5.4.0-1135.142+fips1 | < 5.15.0-1070.79+fips1

• ubuntu•linux-bluefield

  all | < 5.4.0-1090.97 | < 5.15.0-1050.52

• ubuntu•linux-fips

  all | < 5.4.0-1104.114 | < 5.15.0-118.128+fips1 | < 6.8.0-78.78+fips1

• ubuntu•linux-gcp

  all | all | < 5.4.0-1134.143 | < 5.15.0-1066.74 | < 6.8.0-1012.13

• ubuntu•linux-gcp-4.15

  all

• ubuntu•linux-gcp-5.11

  all

• ubuntu•linux-gcp-5.13

  all

• ubuntu•linux-gcp-5.15

  < 5.15.0-1066.74~20.04.1

• ubuntu•linux-gcp-5.19

  all

• ubuntu•linux-gcp-5.3

  all

• ubuntu•linux-gcp-5.4

  < 5.4.0-1134.143~18.04.1

• ubuntu•linux-gcp-5.8

  all

• ubuntu•linux-gcp-6.2

  all

• ubuntu•linux-gcp-6.5

  all

• ubuntu•linux-gcp-6.8

  < 6.8.0-1012.13~22.04.1

• ubuntu•linux-gcp-fips

  all | < 5.4.0-1134.143+fips1 | < 5.15.0-1066.74+fips1

• ubuntu•linux-gke

  all | < 5.15.0-1064.70 | < 6.8.0-1008.11

Showing first 50 affected entries in server-rendered view.

References (35)

• https://git.kernel.org/stable/c/e137e2ba96e51902dc2878131823a96bf8e638ae
• https://git.kernel.org/stable/c/6466ee65e5b27161c846c73ef407f49dfa1bd1d9
• https://git.kernel.org/stable/c/06acb75e7ed600d0bbf7bff5628aa8f24a97978c
• https://git.kernel.org/stable/c/e97e16433eb4533083b096a3824b93a5ca3aee79
• https://git.kernel.org/stable/c/8960ff650aec70485b40771cd8e6e8c4cb467d33
• https://git.kernel.org/stable/c/955b5b6c54d95b5e7444dfc81c95c8e013f27ac0
• https://git.kernel.org/stable/c/eb86f955488c39526534211f2610e48a5cf8ead4
• https://git.kernel.org/stable/c/adf0398cee86643b8eacde95f17d073d022f782c
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OTB4HWU2PTVW5NEYHHLOCXDKG3PYA534/
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DW2MIOIMOFUSNLHLRYX23AFR36BMKD65/
• https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html
• https://lists.debian.org/debian-lts-announce/2024/06/msg00019.html
• https://security.netapp.com/advisory/ntap-20240926-0001/
• https://ubuntu.com/security/CVE-2024-27399
• https://www.cve.org/CVERecord?id=CVE-2024-27399
• https://git.kernel.org/linus/adf0398cee86643b8eacde95f17d073d022f782c
• https://ubuntu.com/security/notices/USN-6949-1
• https://ubuntu.com/security/notices/USN-6950-1
• https://ubuntu.com/security/notices/USN-6951-1
• https://ubuntu.com/security/notices/USN-6952-1
• https://ubuntu.com/security/notices/USN-6953-1
• https://ubuntu.com/security/notices/USN-6955-1
• https://ubuntu.com/security/notices/USN-6956-1
• https://ubuntu.com/security/notices/USN-6957-1
• https://ubuntu.com/security/notices/USN-6950-2
• https://ubuntu.com/security/notices/USN-6950-3
• https://ubuntu.com/security/notices/USN-6949-2
• https://ubuntu.com/security/notices/USN-6952-2
• https://ubuntu.com/security/notices/USN-6951-2
• https://ubuntu.com/security/notices/USN-6951-3
• https://ubuntu.com/security/notices/USN-6950-4
• https://ubuntu.com/security/notices/USN-6951-4
• https://ubuntu.com/security/notices/USN-6979-1
• https://ubuntu.com/security/notices/USN-7019-1
• https://security-tracker.debian.org/tracker/CVE-2024-27399